From e00d2c2d4aead747d0fbee99001b00612d1082b0 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 16 Oct 2007 23:31:01 -0700 Subject: [PATCH] fuse: truncate on spontaneous size change Memory mappings were only truncated on an explicit truncate, but not when the file size was changed externally. Fix this by moving the truncation code from fuse_setattr to fuse_change_attributes. Yes, there are races between write and and external truncation, but we can't really do anything about them. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dir.c | 46 +++++++++++++--------------------------------- fs/fuse/inode.c | 25 ++++++++++++++++++++----- 2 files changed, 33 insertions(+), 38 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 35e5cab..29fef75 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -980,23 +980,6 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg) } } -static void fuse_vmtruncate(struct inode *inode, loff_t offset) -{ - struct fuse_conn *fc = get_fuse_conn(inode); - int need_trunc; - - spin_lock(&fc->lock); - need_trunc = inode->i_size > offset; - i_size_write(inode, offset); - spin_unlock(&fc->lock); - - if (need_trunc) { - struct address_space *mapping = inode->i_mapping; - unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); - truncate_inode_pages(mapping, offset); - } -} - /* * Set attributes, and at the same time refresh them. * @@ -1014,7 +997,6 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) struct fuse_setattr_in inarg; struct fuse_attr_out outarg; int err; - int is_truncate = 0; if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { err = inode_change_ok(inode, attr); @@ -1024,7 +1006,6 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) if (attr->ia_valid & ATTR_SIZE) { unsigned long limit; - is_truncate = 1; if (IS_SWAPFILE(inode)) return -ETXTBSY; limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; @@ -1051,21 +1032,20 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) request_send(fc, req); err = req->out.h.error; fuse_put_request(fc, req); - if (!err) { - if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { - make_bad_inode(inode); - err = -EIO; - } else { - if (is_truncate) - fuse_vmtruncate(inode, outarg.attr.size); - fuse_change_attributes(inode, &outarg.attr); - fi->i_time = time_to_jiffies(outarg.attr_valid, - outarg.attr_valid_nsec); - } - } else if (err == -EINTR) - fuse_invalidate_attr(inode); + if (err) { + if (err == -EINTR) + fuse_invalidate_attr(inode); + return err; + } - return err; + if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) { + make_bad_inode(inode); + return -EIO; + } + + fuse_change_attributes(inode, &outarg.attr); + fi->i_time = time_to_jiffies(outarg.attr_valid, outarg.attr_valid_nsec); + return 0; } static int fuse_getattr(struct vfsmount *mnt, struct dentry *entry, diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 95c8a97..b584de3 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -109,20 +109,24 @@ static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) return 0; } +static void fuse_truncate(struct address_space *mapping, loff_t offset) +{ + /* See vmtruncate() */ + unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); + truncate_inode_pages(mapping, offset); + unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); +} + void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) { struct fuse_conn *fc = get_fuse_conn(inode); - if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size) - invalidate_mapping_pages(inode->i_mapping, 0, -1); + loff_t oldsize; inode->i_ino = attr->ino; inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777); inode->i_nlink = attr->nlink; inode->i_uid = attr->uid; inode->i_gid = attr->gid; - spin_lock(&fc->lock); - i_size_write(inode, attr->size); - spin_unlock(&fc->lock); inode->i_blocks = attr->blocks; inode->i_atime.tv_sec = attr->atime; inode->i_atime.tv_nsec = attr->atimensec; @@ -130,6 +134,17 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) inode->i_mtime.tv_nsec = attr->mtimensec; inode->i_ctime.tv_sec = attr->ctime; inode->i_ctime.tv_nsec = attr->ctimensec; + + spin_lock(&fc->lock); + oldsize = inode->i_size; + i_size_write(inode, attr->size); + spin_unlock(&fc->lock); + + if (S_ISREG(inode->i_mode) && oldsize != attr->size) { + if (attr->size < oldsize) + fuse_truncate(inode->i_mapping, attr->size); + invalidate_mapping_pages(inode->i_mapping, 0, -1); + } } static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) -- 2.7.4